Q.1
Pick out the wrong statement:
Q.2
Drying of a solid involves __________ transfer.
Q.3
For absorbing a sparingly soluble gas in a liquid, the
Q.4
Raschig ring made of procelain cannot be used for treating concentrated
Q.5
Pick out the wrong statement.
Q.6
At equilibrium the concentration of water in vapour phase (C*)in kg/m³ of air space and the amount of water (m) adsorbed per kg of dry silica gel are related by, C* = 0.0667m. To maintain dry conditions in a room of air space 100m³ containing 2.2 kg of water vapour initially, 10 kg of dry silica gel is kept in the room. The fraction of initial water remaining in the air space after a long time (during which the temperature is maintained constant) is
Q.7
Alcohol is dehydrated using __________ distillation.
Q.8
Rose oil is extracted from rose leaves using __________ distillation.
Q.9
Components, having widely different boiling point in a binary mixture, can be separated using __________ distillation.
Q.10
In a forced draft cooling tower, water is cooled from 95 to 80°F by exposure to air with a wet bulb temperature of 70°F. In this case, the
Q.11
During sensible cooling process
Q.12
Which of these columns incurs the lowest pressure drop?
Q.13
Back-trapping in a distillation column
Q.14
Agitator is provided in a crystalliser for
Q.15
Chemisorption (chemical adsorption) is
Q.16
The dimension of diffusivity is same as that of the
Q.17
Mass transfer co-efficient varies as DAB0.5, according to the __________ theory.
Q.18
Mass transfer co-efficient is directly proportional to DAB according to the __________ theory.
Q.19
Fenske-Underwood equation used for calculating the minimum number of theoretical plates in distillation column is valid for
Q.20
Steam distillation is used to separate
Q.21
According to Chilton-Colburn analogy for mass transfer, NSt.NSc2/3 is equal to
Q.22
Desirable value of absorption factor in an absorber is
Q.23
Bound moisture is that liquid which exerts an equilibrium vapor pressure __________ that of the pure liquid at the given temperature.
Q.24
Minimum reflux ratio in a distillation column results in
Q.25
Pick out the wrong statement.
Q.26
The percentage humidity is less than the relative humidity only at __________ percent humidity.
Q.27
Unsaturated air (with dry bulb temperature and dew point being 35°C and 18°C respectively) is passed through a water spray chamber maintained at 15°C. The air will be cooled
Q.28
Which of the following is an undesirable property in a tower packing?
Q.29
The most economical range of absorption factor is
Q.30
With increase in temperature, the leaching rate increases because of the
Q.31
Mechanism of moisture removal in case of freeze drying of food stuff is by
Q.32
Very tall packed towers are divided into series of beds to
Q.33
Out of two equilibrium curves, first one lies above the diagonal and the second lies below the diagonal in the x-y plot. It means that separation by distillation is
Q.34
Leaching of coarse solid lumps is also termed as
Q.35
The caking of crystals can be prevented by
Q.36
A plait point is the point on the solubility curve, where the tie line reduces to a point. What is the number of plait point for a ternery system containing twopairs of partially miscible liquids?
Q.37
Under conditions of flooding in packed tower, the gas pressure drop
Q.38
Which of the following adsorbent is used to decolourise yellow glycerine?
Q.39
The value of L/mG ratio for economical absorption operation ranges from
Q.40
Swenson-Walker crystalliser is a __________ unit
Q.41
The 'shanks system' of leaching (i.e., counter-current multiple contact leaching) is used for
Q.42
__________ is the temperature at which a gas-vapor mixture becomes saturated, when cooled at constant total pressure out of contact with a liquid.
Q.43
Advantage of continuous drying over batch drying is that the
Q.44
In a single stage extraction process, 10 kg of pure solvent S (containing no solute A) is mixed with 30 kg of feed F containing A at a mass fraction xf = 0.2. The mixture splits into an extract phase E and a raf-finate phase R containing A at xB = 0.5 and xR = 0.05 respectively. The total mass of the extract phase is (in Kg)
Q.45
In case of __________ distillation, a solvent is added to alter the relative volatility of the mixture to be separated.
Q.46
Dew point of an air-water vapor mixture
Q.47
__________ extractor is used for the concentration of radioactive nuclear waste.
Q.48
Liquid diffusivity is of the order of __________ cm² /second.
Q.49
Stefan's law describes the mass transfer by
Q.50
In McCabe-Thiele method of theoretical plate calculation for a distillation column, the operating lines of stripping and rectifying sections coincide with the diagonal at __________ reflux.
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